The present invention relates to a loading and unloading device for an evacuatable chamber and a process for the loading and unloading of such a treatment chamber.
Loading and unloading devices of this general type are used to feed work pieces to be processed, for example, machined parts to be coated, or to remove the coated machined pieces from the coating apparatus. For this purpose, coating apparatuses of this type have an in-/out- transport station into or out of which the workpieces are transportable. The in-or out- transport process itself requires that the transport station is to be evacuated for the aeration, or for the processing of the workpiece in the vacuum chamber.
In the operation of the known generic type loading/unloading devices (handling devices), for the unloading of the previously aerated transport station, first the transport station door is opened by a traverse drive, after which a handling arm travels into the transport station and grasps a carrying base bearing the machined pieces. This first handling arm then travels out of the transport station far enough that a second handling arm with a carrying base bearing an uncoated machined piece can be processed. After that, the second handling arm transfers the carrying base to a retaining device in the transport station. Subsequent to this transfer, the second handling arm is withdrawn from the transport station and the latter is closed with the transverse drive transport station door. Afterwards, the workpieces introduced into the vacuum chamber are transferred to a processing station within the vacuum chamber.
A disadvantage of this known loading/unloading device is, that the amount of time for the loading or the unloading from the transport station in proportion to the entire processing time required for the coating process is great. Especially with so-called short time coating apparatuses it is desirable to keep the cycle time, that is the overall time elapsed between two sending cycles, as small as possible.